Nick Bennett, pictured with his partner Rowena Hardy, was among a group of hikers attacked in Papua New Guinea.

An hour later, six men appeared with bush knives, spears, a .303 rifle and a home-made gun.

‘‘I was in my tent and I heard a lot of shouting and I thought the boys had actually found something, an animal or something,’’ he told the ABC at Cairns Airport.

When he stepped outside, Mr Bennett copped a blow to the head.

‘‘I thought I’d been shot and what I realised after was that I had been clubbed with a rifle barrel and it had opened my head up. So I was bleeding immediately, just confused,’’ he said.

‘‘I looked up and could see a boy with a mask on walking away and there was shouting ...

‘‘All I could really do was hold my head in my hands and I ordered the others down.

‘‘When I looked to my left, sort of crouching, I could just see one of the guys actually just attacking the porters with a bush knife.

‘‘There was one guy with a rifle, one guy had a pipe gun and a bush knife and they would come at us.

‘‘There was one person who appeared to be controlling it, but they would go back up to where the porters were and attack again and again.’’

Two porters were killed, one of the Australians was slashed, another was speared and others were beaten. Six other porters were also stabbed.

Bleeding and terrified, the injured men hiked for four hours in the dark, led by Australian tour leader Christina King, back to safety, carrying the porters’ bodies.

Mr Bennett’s long-time partner Rowena Hardy was only able to make a brief comment on the shocking attack on Thursday morning.

"He’s OK. He’s on his way home," she told Fairfax Media.

"He’s going to be home as soon as possible."

The head of PNG Trekking, Mark Hitchcock, said the hikers were mainly middle-aged and included Mr Bennett and Mr Ward, as well as one Sydney man and five Victorians. One member of the group was an Australian-based New Zealander.

"It’s early days but robbery would appear to be the motive – after all, they took everything," Mr Hitchcock said.

The Black Cat Track, used by gold prospectors in the 1920s and the scene of battles between Australian and Japanese troops, remains a rarely attempted trek and the large toll among porters recruited from villages along the six-day route suggests the attack may have been local score-settling.

Although the motive for the attack is not clear, some reports have suggested it could be related to a disagreement between porters from PNG’s lowlands and locals living in the highlands.

PNG Prime Minister Peter O’Neill has condemned the attack, saying the assailants will face the death penalty when caught.

"These are appalling crimes, and they attract the death penalty under laws passed by the National Parliament since the last election," Mr O’Neill said in a statement.

"At a time when we are seeking to increase tourism these crimes are an obvious setback – but we must not let them deter tourists and travellers generally visiting Papua New Guinea, and our own people helping visitors in their travels."

Local villagers have been tracking the attackers and about 20 police officers have been sent to join the hunt.

In the wake of the attack, the Department of Foreign Affairs has advised trekkers to avoid the Black Cat Track until the incident has been fully investigated.